Urinary glyphosate biomonitoring of sprayers in vegetable farm in Thailand.

In Thailand, glyphosate is popular herbicide to control pests in the agricultural sector. This study aimed to measure glyphosate exposure concentrations through inhalation, dermal contact, and urinary glyphosate concentrations among 43 vegetable farmers spraying glyphosate in Bungphra Subdistrict, Phitsanulok Province. Four types of spraying equipment were used, manual pump backpack (n = 3), motorized spray backpack (n = 22), battery pump backpack (n = 16), and high pressure pump (n = 2). Breathing zone air samples were collected using glass fiber filters; dermal contact samples were collected using 100 cm2 cotton patches attached on 10 body locations and urine samples were collected at 3 time points: morning void urine the day before spraying, the end of spraying event, and the morning void urine the next day of spraying. The results showed that the geometric mean (GM; geometric standard deviation [GSD]) of breathing zone concentrations of glyphosate exposure were 9.37 (10.17) µg/m3. The GM (GSD) of total dermal patches exposure concentrations were 7.57 (0.01) mg/h. The legs, back, and arms were the most exposed body areas. The GM (GSD) of urinary glyphosate was found highest among vegetable farmers using manual backpack 46.90 (1.35) µg/g creatinine. Farmers should wear masks and boots to reduce glyphosate exposure by inhalation and dermal contact.

Factors Associated with Musculoskeletal Disorders Among Female Readymade Garment Workers in Bangladesh: A Comparative Study Between OSH Compliant and Non-Compliant Factories.

PURPOSE: Musculoskeletal Disorders (MSDs) are one of the most common occupational diseases responsible for work restriction and absenteeism. The purpose of the study was to compare the prevalence of MSDs between ready-made garment (RMG) factories that are compliant versus non-compliant with International Labor Organization (ILO) based Occupational Safety and Health (OSH) standards, and to identify other factors associated with a higher prevalence of MSDs. METHODS: A multicenter cross-sectional study was conducted among 410 randomly selected female workers (age: >18 years; ≥1 year of work experience) from 12 randomly selected RMG factories in the Dhaka district of Bangladesh from February to December 2019. Factories were stratified as OSH compliant or non-compliant. Data were collected using a structured questionnaire consist of socio-demographic, work-related factors, and Nordic Musculoskeletal Questionnaire (NMQ) for MSD assessment. Robust Poisson regression was used to investigate the association of MSDs with OSH compliance, socio-demographic and other work-related factors. RESULTS: Respondents' mean age was 26.9 ± 5.9 years. A total of 235 (57%) of the workers reported musculoskeletal pain in at least one body part during the last month. Among the nine reported MSDs, the prevalence of lower back pain was highest (41%) followed by pain in the knees (33%). Multivariable analysis showed lower prevalence of any MSD among workers in OSH compliant factories [aPR = 0.43, 95% CI: 0.31-0.58], and workers with regular working hours (8 hrs/day) [aPR = 0.79, 95% CI: 0.62-1.00]. The risk of developing any MSD was significantly higher for age group 25-30 years [aPR = 1.16, 95% CI: 1.01-1.33] and age group ≥31 years [aPR = 1.21, 95% CI: 1.04-1.1.39]. CONCLUSION: The study found a high burden of musculoskeletal disorders among female RMG workers, especially those in non-OSH compliant factories that work long hours. Enforcement of minimum ILO-based OSH standards and introduction of low-cost interventions to improve working conditions in non-compliant factories would help sustain the pace of development in this sector in Bangladesh, and ensure the health of the women who work there.

ORGANOPHOSPHATES IN MECONIUM OF NEWBORN BABIES WHOSE MOTHERS RESIDED IN AGRICULTURAL AREAS OF THAILAND.

Organophosphates (OPs) are widely used for pest and weed control in many countries including Thailand. In addition to causing environmental pollution, OPs affect human health by overstimulating neurotoxicants, and OP exposure during pregnancy can lead to adverse health effects of mothers and their fetuses. Using gas chromatography-mass spectrometry with a dedicated extraction protocol to identify OPs in meconium of newborn babies (n = 68) from hospitals in Amnat Charoen, Kanchanaburi and Nakhon Sawan provinces, agricultural regions of Thailand, among ten OP types analyzed, eight were detected in 98% of meconium samples (chlorpyrifos (median ± interquartile range (IQR) 0.08 ± 0.03-0.16 µg/g) in 32% of samples, demeton-s-methyl (0.35 ± 0.26-0.49 µg/g) in 73%, dichlorvos (0.67 ± 0.58-0.71 µg/g) in 38%, dimethoate (0.43 ± 0.09-1.56 µg/g) in 50%, ethion (0.21 ± 0.19-0.26 µg/g) in 12%, malathion (0.28 ± 0.15-0.52 µg/g) in 50%, omethoate (5.63 ± 4.85-8.57 µg/g) in 34%, and tolclofos-methyl (0.08 ± 0.03-0.10 µg/g) in 41%). There are no significant differences in these parameters from babies whose mothers did and did not work in the agricultural or who lived near (within one km) and distant from farmland. The findings should be of benefit in developing programs to protect pregnant women and newborn babies from exposure to OP pesticides.

Hearing Loss in Agricultural Workers Exposed to Pesticides and Noise.

Agricultural workers who have concurrent exposure to pesticides and noise are at increased risk of hearing loss. We recruited 163 Thai conventional and 172 organic farmers to answer our questionnaires about personal demographics, agricultural activities, and pesticide and agricultural machinery use. This information was used to calculate the years of conventional (pesticide use) farming and the years of agricultural noise exposure, and to estimate semiquantitative metrics for pesticide exposure (cumulative intensity score-years) and cumulative noise exposure (dB(A)-years) for each conventional farmer. All participants underwent pure tone audiometric testing. The mean hearing threshold in the low-frequency band (0.5-2 kHz) and high-frequency band (3-6 kHz) were used for analysis. Years involved in conventional farming and years using agricultural machinery were associated with an increase in the average hearing threshold for the high-frequency band after controlling for age, ever exposed to industrial noise and cigarette smoking. The highest category of cumulative insecticide exposure (score-years), cumulative organophosphates exposure (score-years) and cumulative noise exposure (dB(A)-years) were also associated with an increased high-frequency band hearing threshold among conventional farmers. Results from the full cohort and the subcohort of conventional farmers support each other and the hypothesis that pesticide and noise have an additive effect on hearing, since no model interactions were significant.

Respiratory effects among rubberwood furniture factory workers in Thailand.

Respiratory symptoms and pulmonary function were examined among 89 rubberwood furniture factory workers. Acute and chronic irritant symptoms were assessed, lung function was measured both pre- and post-shift and personal inhalable dust exposure determined. The only symptoms with a significant increase among high dust level-exposed workers (>1 mg/m(3)) were those related to nasal irritation. High dust level-exposed workers had a significant cross-shift decrease in forced expiratory volume in 1 second/forced vital capacity (FEV(1)/FVC) compared with low dust level-exposed workers and increases in inhalable dust concentration levels (mg/m(3)) were significantly associated with decreases in the peak expiratory flow (PEF) across the work shift. For percent predicted pulmonary function levels, a significant decrement in PEF was found for high versus low rubberwood dust level-exposed workers, after controlling for confounders. These findings suggest the need for an occupational standard for rubberwood dust in Thailand.

Health effects of people living close to a petrochemical industrial estate in Thailand.

OBJECTIVE: An acute health effect of people living near the petrochemical industrial estate in Thailand was assessed using a panel study design. MATERIAL AND METHOD: The populations in communities near the petrochemical industrial estates were recruited. The daily air pollutant concentrations, daily percentage of respiratory and other health symptoms reported were collected for 63 days. The effect of air pollutants to reported symptoms of people were estimated by adjusted odds ratios and 95% confidence interval using binary logistic regression. RESULTS: The significant associations were found with the adjusted odds ratios of 38.01 for wheezing, 18.63 for shortness of breath, 4.30 for eye irritation and 3.58 for dizziness for total volatile organic compounds (Total VOCs). The adjusted odds ratio for carbon monoxide (CO2) was 7.71 for cough, 4.55 for eye irritation and 3.53 for weakness and the adjusted odds ratio for ozone (O3) was 1.02 for nose congestion, sore throat and 1.05 for phlegm. CONCLUSION: The results showed that the people living near petrochemical industrial estate had acute adverse health effects, shortness of breath, eye irritation, dizziness, cough, nose congestion, sore throat, phlegm and weakness from exposure to industrial air pollutants.

Health risk assessment of volatile organic compounds in a high risk group surrounding Map Ta Phut industrial estate, Rayong Province.

OBJECTIVE: The health risks of a high-risk group, surrounding Map Ta Phut industrial estate, Rayong, which may be exposed to VOCs through inhalation of contaminated air and dermal contact of contaminated water were assessed. MATERIAL AND METHOD: The health risk was assessed for 19 subjects categorized as children, adult and elderly from Ban plong and Nongfab communities following the US Environmental Protection Agency (EPA) method. The VOC concentrations in ambient air and ground water were monitored by Pollution Control Department (PCD), Ministry of Natural Resources and Environment to represent average VOC exposure of subjects. RESULTS: The lifetime cancer risk of VOCs exposure from inhalation and dermal contact with ground water were 1.32 x 10(-7)-5.21 x 10(6) for elderly 1.18 x 10(-7)-6.20 x 10(-6)for adult and 8.93 x 10(-7)-5.93 x 10(-6) for children. For non-cancer risk, the hazard index was 0.44 for elderly, 0.38-0.42 for adult and 0.55 for children. CONCLUSION: The lifetime cancer risk of the high-risk group living near Map Ta Phut industrial estate was in acceptable range for elderly, adult and children. For non-cancer risk, it is also acceptable.

The urinary cotinine and serum 25 hydroxyvitamin D levels in male smokers.

OBJECTIVE: To assess urinary cotinine and the effects of smoking on 25(OH)D levels in 67 male smokers. MATERIAL AND METHOD: Urine and blood specimens were analyzed for cotinine and serum 25 hydroxyvitamin D (25(OH)D) concentrations by high performance liquid chromatography (HPLC) and chemiluminescent immunoassay, respectively. The accuracy, precision and detection limit of the HPLC method were also tested. RESULTS: The detection limit of urinary cotinine was 0.02 microg/ml. The recoveries of cotinine concentrations of 0.15-2.0 microg/ml were greater than 95%. Only 23.9% of smokers had sufficient levels of serum 25(OH)D at least 30 ng/ml. The smokers were divided into dairy co-operative smokers and other smokers. The average urinary cotinine concentrations of 1,421.42 and 1,866.52 microg/g creatinine were not significant different in dairy co-operative smokers and other smokers whereas the average 25(OH)D of 29.09 and 22.65 ng/ml, respectively, were significantly different at p-value of < 0.001. CONCLUSION: The 42.86% and 10.26% of the diary co-operative smokers and other smokers had sufficient serum 25(OH)D levels to prevent osteoporosis.

Exposure to trinitrotoluene and health effects among workers in an artillery and ammunition plant.

OBJECTIVE: To determine urinary trinitrotoluene (TNT), 2-amino-4, 6-dinitrotoluene (2ADNT) and 4-amino-2, 6-dinitrotoluene (4ADNT) and health effects upon workers in an ammunition plant. MATERIAL AND METHOD: The urine samples from forty munition workers and forty office workers were monitored for TNT and its metabolites by gas chromatography-mass spectrometry. The workers were interviewed with a questionnaire. RESULTS: The median levels of TNT and its metabolites were 112.84 and ranged from non-detectable (ND) to 1,833.81 mg/L. Median levels for 2ADNT were 11.66, ranging from ND to 360.89 mg/L. Median levels for 4ADNT were 19.95 and ranged from ND to 314.28 mg/L. There were significant correlations between TNT and 2ADNT in urine (r = 0. 700, p-value < 0.001), as well as for TNT and 4ADNT (r = 0.783, p-value < 0.001). Exposed workers reported eye, nose and throat irritations, weakness and headaches with considerably higher frequency than non-exposed workers. CONCLUSION: TNT levels in urine were strongly associated with 4ADNT and 2ADNT levels. Workers exposed to TNT complained of nose, throat and eye irritation, along with overall weakness and headaches.

Ethion exposure and biological monitoring in vegetable farmers.

OBJECTIVE: To modify the method of analysis of urinary diethyl phosphate (DEP) in order to determine the relationship between atmospheric ethion concentration and urinary DEP concentration. MATERIALS AND METHOD: A cross-sectional study was conducted by collecting atmospheric ethion in the breathing zone of 28 farmers following the NIOSH 5600 method. Urine samples were also collected to analyze urinary DEP concentrations by a modified method using a Gas Chromatography-Flame Photometric Detector (FPD). RESULTS: The average atmospheric ethion concentration in the breathing zone of farmers was 0.036 +/- 0.018 mg/m3. The average urinary DEP in pre-shift and post-shift was 0.030 +/- 0.06 and 0.851 +/- 1.80 mg/g of creatinine respectively. The average DEP during work shifts was 0.53 +/- 0.27, and ranged from 0.12 to 1.16 mg/g of creatinine. A high correlation coefficient (r = 0.645) was found between atmospheric ethion concentrations and urinary DEP concentrations at p < 0.001. CONCLUSION: The modified method provided a reliable result and the urinary DEP during work shifts was found to be a reliable biomarker of ethion exposure.

Design and development of ultraviolet germicidal irradiation device for controlling airborne bacteria in the workplace.

OBJECTIVE: To design and develop an ultraviolet germicidal irradiation (UVGI) device for controlling airborne bacteria in the workplace of hospitals. MATERIAL AND METHOD: The constructed UVGI device was a chamber, consisting of a return air grille, an air supply grille, two 30-watt ultraviolet lamps and a cross flow fan inside the chamber. The efficiency of the UVGI device was tested at three different flow rates of 15.7, 31.6 and 46.1 m3/min, respectively by collecting bacteria samples before and after operating the device for 30, 60, 90 and 120 minutes. RESULTS: The efficiency of the UVGI device at flow rates of 15.7, 31.6 and 46.1 m3/min was 60.6, 92.8 and 80.8%, respectively and the bacteria concentration was reduced to less than 100 cfu/m3, except at the flow rate of 15.7 m3/min. The application of the UVGI device in the specimen-received room showed that the concentration of bacteria was reduced to less than 100 cfu/m3 after 180 minutes. CONCLUSION: The constructed UVGI device was effective to reduce airborne bacteria in workplace of hospital.

Assessment of nicotine inhalation exposure and urinary cotinine of tobacco processing workers.

OBJECTIVE: To study the composition of tobacco dust, atmospheric nicotine concentration, urinary cotinine excretion and the subjective symptoms of workers in dry tobacco leaf preparation. MATERIAL AND METHOD: The tobacco dust in air of the breathing zone of workers and the urine samples of these workers and a comparison group were collected and analyzed by GC/MS. The accuracy, precision and detection limit of the methods were determined. RESULTS: The tobacco dust contained nicotine and atrazine (a herbicide). The average atmospheric nicotine was 0.105 mg/m3 and urinary cotinine concentrations of post tobacco curing process workers was 3.084 microgram/ml. Moreover, there was a significant correlation between the atmospheric nicotine dust and urinary cotinine excretion (r = 0.987, p < 0.05). The health symptoms of headache, nausea, weakness, dizziness, and increased perspiration reported among workers had a significant relationship with the job characteristics of the post tobacco curing process workers, with a p-value < 0.05. CONCLUSION: Nicotine dust contained a herbicide called atrazine. Nicotine concentrations were highest in the post tobacco curing process where workers reported a lot of adverse symptoms. Urinary cotinine can be used as a biomarker of tobacco dusts' exposure in dry tobacco leave preparation areas.

Assessment of nicotine dermal contact and urinary cotinine of tobacco processing workers.

OBJECTIVE: To assess the dermal contact of nicotine dust, subjective symptoms and urinary cotinine of post curing tobacco workers. MATERIAL AND METHOD: Dermal hand wipes of residual nicotine dust samples, morning urine samples and subjective symptoms were collected from 30 workers. The hand-wipe samples and urine samples were analyzed for nicotine and cotinine by a GC/MS, respectively. RESULTS: The average amount of nicotine on the hands of workers was 0.24 microgram/cm2, while the average urinary cotinine concentration of workers was 3.08 microgram/ml. Moreover, there was a significant correlation between nicotine residue on hands and urinary cotinine excretion at r = 0.978, p < 0.05. There was also a significant relationship between the occupational related nicotine residue on hands and the number of subjective symptoms reported (p < 0.05). CONCLUSION: The nicotine residue on hands could be used as an indicator of occupational nicotine dust exposure which might affect the health of tobacco workers.

High performance liquid chromatography for determination of urinary metabolites of toluene, xylene and styrene and its application.

The purpose of this research was to determine mandelic, phenylglyoxylic, hippuric, o-, m- and p-methylhippuric acids, the six urinary metabolites of styrene, toluene and xylene by high performance liquid chromatography (HPLC). These metabolites were extracted in an acid medium, transferred into a basic solution and back extracted again using ethyl acetate, and the organic phase was evaporated to dryness under a compressed air flow at room temperature. The residue obtained was dissolved in 1 ml mobile phase solution of 0.01 M potassium orthophosphate in 0.3% acetic acid (adjusted to a pH of 2.5 with orthophosphoric acid):tetrahydrofuran:acetonitrile(87:5:8) and 100 microl was injected into a HPLC equipped with a 4.6 x 250 mm ODS3-C18 reversed phased column and ultraviolet (UV) detector at a wavelength of 254 nm. All metabolites were clearly separated within 21 minutes. The detection limits of the method were 1.1 ng/ml for PGA, 4.9 ng/ml for HA, 17.0 ng/ml for MA, 2.5 ng/ml for o-MHA, 1.7 ng/ml for p-MHA and 2.0 ng/ml for m-MHA. The percent recoveries of the six metabolites were 99.2-101.8% with percent coefficients of variation of less than 2%. The method was applied to the analysis of urine samples of twelve workers exposed to toluene, xylene and styrene in a paint factory. The 5-day post-shift urinary excretions of the six metabolites in these workers are presented. The metabolites were found at levels greater than the Biological Exposure Index (BEI) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).

Development of a sampling and analysis method for 4-vinyl-1-cyclohexene in air.

The purpose of this research was to develop an applicable sampling and analytical method to determine airborne 4-vinyl-1-cyclohexene concentrations which are usually found in the atmosphere of polybutadiene factories. A solid sorbent tube, containing two sections (100 mg in the front and 50 mg in the back) of activated coconut-shell charcoal was chosen for sampling 4-vinyl-1-cyclohexene vapor. The 4-vinyl-1-cyclohexene in the charcoal samples was desorbed with carbon disulfide and analyzed by gas chromatography equipped with a flame ionization detector. The suitable air flow rate, adsorption capacity, sample storage stability, desorption efficiency and reliability of the method for sampling and analysis of 4-vinyl-1-cyclohexene were evaluated. The method was applied to sampling and analysis of 4-vinyl-1-cyclohexene in the rubber industry. The results indicated a suitable air flow rate of 0.3 to 1.5 l/min. The adsorption capacity of 4-vinyl-1-cyclohexene on 100 mg of charcoal was 0.2134 mg. The 4-vinyl-1-cyclohexene adsorbed on the charcoal was stable for 7 d at room temperature or 21 d in a refrigerated condition. The average percent desorption efficiency of 4-vinyl-1-cyclohexene ranged from 90.45% to 97.04% with the loaded amount ranging from 0.412 to 8.250 microg using 1 ml carbon disulfide. The limit of detection of 4-vinyl-1-cyclohexene was 0.044 ng. The average percent recoveries (n=6) of 4-vinyl-1-cyclohexene adsorbed on charcoal ranging from 0.46 to 8.87 microg were 96.78-102.87% with relative standard deviations (RSDs) of 0.34-1.92%, respectively. The concentrations of 4-vinyl-1-cyclohexene ranged from 0.011 to 0.105 mg/m(3) in the working environment of a polybutadiene factory.